Re: tie over clef change

[Aaron Hill]

On 2020-09-26 9:04 am, Dan Eble wrote:
> > On Sep 26, 2020, at 09:41, Dan Eble <dan@faithful.be> wrote:
> >
> > On Sep 26, 2020, at 08:55, Werner LEMBERG <wl@gnu.org> wrote:
> > > Despite Gould's “incorrect” verdict, here is an example from an old 
> > > UE
> > > edition of Liszt's “Liebestraum No. 1”, which demonstrates that ties
> > > over clef changes *do* happen and make sense sometimes...
> > >
> > > I still think that LilyPond should support that, handling the tie 
> > > like
> > > a slur in this case.
> >
> > That's a very good example.  It's hard to imagine any reasonable 
> > alternative.
> >
> > What kind of grob would an editor expect here? a Tie because it 
> > connects notes of the same pitch, or a Slur because it connects notes 
> > at different staff positions? (or something else?)
>
> I'll answer my own question.  A tie from d♯ to e♭ generates a Tie
> grob, so for consistency, this should be a Tie that looks like a slur.

An idea: Could Tie gain a new Boolean property that controls whether to 
slope a Tie or keep it horizontal when the end points do not share the 
same Y position?  That would give the user an easy way to have both 
options.

A more complex idea: This new property could be a number-pair? that 
provides even more control over the Y position of the ends.  Each number 
is an index value (e.g. LEFT, CENTER, RIGHT).  If the value is LEFT, 
then it is the left note's Y position that is used; RIGHT maps to the 
right note's Y position; and CENTER is the average of the two values.  
(Technically, any index value could be used to interpolate the Y 
positions.)  Simple horizontal ties that stick to the left note would 
use #'(-1 . -1), and #'(1 . 1) would hug the right note.  #'(-1 . 1) 
would slope the Tie like a Slur.


-- Aaron Hill